On April 15, 1861, just three days after the attack on Fort Sumter, President Abraham Lincoln issued a proclamation calling forth the state militias, to the sum of 75,000 troops, in order to suppress the rebellion. He appealed “to all loyal citizens to favor, facilitate, and aid this effort to maintain the honor, the integrity, and the existence of our National Union.” As days passed, senators noted the tremendous response to the president’s call for troops. “The response of the loyal states to the call of Lincoln was perhaps the most remarkable uprising of a great people in the history of mankind,” wrote Senator John Sherman of Ohio. “Within a few days the road to Washington was opened, but the men who answered the call were not soldiers, but citizens.”

Lincoln’s proclamation also summoned Congress to return for an extraordinary session beginning on July 4, “to consider, and determine, such measures as, in their wisdom, the public safety, and interest, may seem to demand.” From April to July of 1861, in preparation for the rare summertime session, senators were engaged in a variety of war-related activities—rallying support, building the military, crafting essential legislation, and handling constituent requests. John Sherman met with administration officials and worked during these months to recruit military enlistments. He even served as an aide-de-camp in the Union Army, in addition to fulfilling Senate duties. Stephen Douglas met privately with President Lincoln on April 14, then traveled extensively throughout April and May to deliver speeches demanding that partisan battles be put aside in order to rally support for the Union cause. “You all know that I am a very good partisan fighter,” he told the Illinois state legislature on April 25. “I trust you will find me equally a good patriot.” Charles Sumner of Massachusetts advised Lincoln on foreign policy, while Maine’s William Pitt Fessenden tackled issues of finance.